code: def backward_gpu(self, inputs, grad_outputs):
      if not chainer.should_use_cudnn(">=auto", 5000):
          return self._backward(inputs, grad_outputs)
      (theta,) = inputs
      (ggrid,) = grad_outputs
      ggrid_t = cuda.cupy.transpose(ggrid, (0, 2, 3, 1))
  
      gtheta = cuda.cupy.empty_like(theta)
      handle = cudnn.get_handle()
      ggrid_t = cuda.cupy.ascontiguousarray(ggrid_t)
      libcudnn.spatialTfGridGeneratorBackward(
          handle, self.st_desc.value, ggrid_t.data.ptr, gtheta.data.ptr
      )
      return (gtheta,)
  
file_path: chainer/chainer/functions/array/spatial_transformer_grid.py
imports: import numpy
  import chainer
  from chainer import backend
  from chainer.backends import cuda
  from chainer import function
  from chainer.utils import argument
  from chainer.utils import type_check
label_desc: Use image node_id 7 for calling the SpatialTransformerGrid obj's underlying member method code with example usage: obj.backward_gpu(inputs, grad_outputs) and returns: gtheta, self